The hadal zone, also known as the hadopelagic zone, is the deepest region of the ocean, lying within oceanic trenches. Wikipedia

Composed of trench zones, is the delineation for the deepest trenches in the ocean. The hadal zone is found from a depth to the bottom of the ocean of around 6,000 to 11,000 metres and exists in long but narrow topographic V-shaped depressions Wikidata